Sawhorses of one type or another have been used by carpenters and others for many centuries and most everyone is aware of the typical sawhorse having a horizontal beam supported at opposing ends by a pair of legs. As one skilled in the art would understand, the dimensions of the sawhorse can be altered to suit particular needs.
The need for a sawhorse is often a temporary one, and between uses it is convenient to knock-down the sawhorse to a more compact and portable form. A knock-downed form allows the sawhorse to be transported more easily to where it is needed so that it can be re-assembled for use. Typically, assembly and disassembly of knock-down sawhorses involved clamps, bolts, screws and nails.
U.S. Pat. No. 4,014,405 to Breisch discloses a knock-down sawhorse which can be assembled without the use of bolts, screws, nails, or clamps. Breisch teaches two pairs of identical legs that each cooperatively fit within a recess along a bottom of a horizontal beam. The horizontal beam is supported at each end by a pair of the identical legs. The cooperating legs securely fit within the recess without the use of bolts, screws, nails or clamps. Breisch's sawhorse is composed of thermoplastic and its legs are not adjustable for leveling the horizontal beam.
U.S. Pat. No. 5,305,850 to McQuiston teaches a horizontal beam having grooves at opposing ends for receiving a corresponding pair of legs. McQuiston's knock-down sawhorse obviates the need for bolts, screws, nails or clamps for assembly of the sawhorse. Similar to Breisch, McQuiston's legs are not adjustable for leveling the horizontal beam.
Very popular in recent times have been the folding or collapsible type sawhorses. As disclosed in U.S. Pat. No. 4,296,834 to Kroger, a folding sawhorse typically has a horizontal beam supported by a pair of legs at each opposing end of the horizontal beam. The two pairs of legs are each pivotally connected to the horizontal beam to allow the pair of legs to pivot longitudinally towards the horizontal beam, thereby collapsing the sawhorse for storage or transportation. Collapsible sawhorses obviate the need to disassemble and re-assemble a sawhorse when storing, transporting or using it.
U.S. Pat. No. 4,804,064 to Coultrup et al. teaches a lightweight collapsible sawhorse that is vertically adjustable. Each of the four legs used in Coultrup's sawhorse is telescopically adjustable in length, allowing a user to adjust a working height of the sawhorse at each end for leveling the sawhorse. Coultrup's telescopic legs can be locked into or released from a position by the use of spring tabs which permits a user to level the sawhorse on uneven working surfaces. As a result, a maximum load bearing capacity of Coultrup's sawhorse is diminished and limited, not by the load bearing capacity of the support legs, but by the load bearing capacity of the spring tabs used to lock each leg in a particular position.
U.S. Pat. No. 5,908,182 to Stang et. al. discloses an adjustable and foldable sawhorse that is also capable of being leveled. Stang's sawhorse comprises a horizontal beam supported at both opposing ends by A-shaped frames and a support frame having two vertical posts interconnecting the two A-shaped frames. Each A-shaped frame is movably supported on the vertical post of the support frame and can be independently adjusted in height to level the sawhorse on uneven working surfaces. Similar to Coultrup's sawhorse, the load bearing capacity of Stang's sawhorse is diminished and limited, not by the load bearing capacity of the support legs, but rather by the load bearing capacity of the support frame.
There is a need for a heavy duty commercial sawhorse that is easily stored, adjustable and is capable of being leveled while maintaining its maximum load bearing capacity.